This invention relates to both targeting system and to a method of manufacturing such a drug targeting system. The invention also relates to a useful method of targeting and delivering drugs, diagnostics and other physiologically effective substances to a target within the mammalian body, for example to the nervous system. This work is motivated by the search of new technologies that enhance the capability to deliver physiologically effective substances like drugs or diagnostically useful agents to a desired target within the mammalian body, including delivering such substances across the blood brain barrier (bbb) which is a generally recognized problem in neuropharmacology.
In a previous patent application (Kreuter et al.; U.S. patent application Ser. No. 08/203,326 and PCT/EP 95/00724 corresponding to WO 95/22963) a novel method of delivering drugs across the blood brain barrier by using nanoparticles to which drugs are complexed (incorporated or adsorbed) and which are then surrounded by a coating made of an appropriate surfactant is taught. The present invention pertains to a similar approach. Particularly, nanosphere drug targeting systems can be obtained now which can achieve the same effect as demonstrated in the prior art description (Kreuter et al., loc. cit) but which can be manufactured by a significantly simplified fabrication method. The present invention teaches a drug targeting system, a method of improved and simplified fabrication and a method of use of such a drug targeting system in the medical field.
Here, nanoparticle fabrication involves the polymerization by using a stabilizer other than dextran 70.000 which allows for the first time that coating the nanoparticle-drug complex with a surfactant, which was deemed a requirement to achieve the desired effect in the prior art (Kreuter et al., loc. cit.) can be omitted. Thus, the present invention teaches a method and composition of nanoparticles which is significantly simplified over prior art drug targeting systems and their method of manufacture. This system allows any drug (“drug” as used herein includes any substance administrable for therapeutic and/or diagnostic purposes) to cross the blood brain barrier (bbb) in order to achieve one or more of the following benefits: reducing the dose of a drug or diagnostic, allowing drugs that normally do not cross the bbb to penetrate into the brain and reducing the peripheral side effects by increasing the relative amount of the drug reaching the brain.